Denial Of Service Attack [Episode 1]

On 6th February 2000, Yahoo portal was shut down for 3 hours. Then retailer Inc. (BUYX) was hit the next day, hours after going public. By that evening, eBay (EBAY), (AMZN), and CNN (TWX) had gone dark. And in the morning, the mayhem continued with online broker E*Trade (EGRP) and others having traffic to their sites virtually choked off. (Business Week Online, 12 February 2000)

On 6th August 2009, twitter was the victim. Lot of people had trouble on logging on twitter,It was brought down by denial of service attack. 
                                                                              -Reported by CNN’s Don Lemon

What is a Denial Of Service Attack?

? Denial of service attack is an attack in which attacker try to crash the system or to make the computer resource unavailable to its legal users, if an attacker is unable to gain access into a server, the attacker most probably will just crash it.
? Denial of service (DOS) attack is the process of sending a large number of packets to the target that interfere with its operation, or just crash it.

Types of DOS attacks:

Common DOS attacks are
? Smurf attack some time refer as Amplification attack, ICMP(Internet Control Message Protocol) flood attack or Fraggle Attack.
? A smurf attack uses spoofing and broadcast addressing to amplify a single packet to multiple packets.
? Three major parties of this attack are.
The attacker
The intermediary (a router) also known as smurf amplifier
The victim

? In Smurf attack an attacker first spoof the source IP address of the victim, generates a large amount of ICMP echo traffic toward IP broadcast addresses. The intermediary receives an ICMP echo request packet directed to the IP broadcast address of their network.

? Each host that receives the broadcast responds back to the real source IP with an echo reply, this attack can be done with both ICMP packets and UDP echo packets(Fraggle attack).

? Turn off the forwarding of directed broadcast on all router ports.
? Configure each hosts and routers not to respond or reply to ping request
? Use network Ingress filtering.

SYN Flooding? SYN flooding is an another type of DOS attack in which an attacker generates Transmission Control Protocol(TCP) request faster of the system processing capabilities, in SYN flooding an attacker take advantages of TCP handshaking process.
? TCP handshaking process involve three steps to establish a connection.
1. In first step client send a TCP Synchronize(SYN) packet to the server.
2. Server receives a SYN packet and send a Synchronize-Acknowledgement (SYNACK)
packet back to the client(host).
3. Client receives SYN-ACK packet and sends Acknowledge(ACK), and the connection is established.

 To Be Continued on the next part we will share some codes to launch a SYN Flooding Attack.

Note: If you enjoyed this post, you might want to subscribe our RSS feed and Email Subscription  or become our Facebook fan! You will get all the latest updates at both the places.
Previous articleLinux VS Windows
Next articleRapidshare | Hotfile Hack
Ehacking Staff
With more than 50 global partners, we are proud to count the world’s leading cybersecurity training provider. EH Academy is the brainchild of Ehacking, which has been involved in the field of training since the past Five years and continues to help in creating professional IT experts.

Most Popular

Top Suggestions To Minimize Cyber Attack Risks

The Cyber Protection and Cyber Attack definition play an important role in maintaining both global security and operational productivity due to the rapid proliferation...

Policing the Dark Web (TOR): How Authorities track People on Darknet

The darknet, especially the TOR network, can be hacked, or the information of the people using it can be extracted in the plain text....

Best VPNs for Android – and Why You Need One Now

Most people protect their laptops and computers from potential cyber-attacks but only consider the cybersecurity of their mobile devices when it’s too late. In recent...

The Levels of the Internet Surface Web, Deep Web, and Dark Web

The internet, invented by Vinton Cerf and Bob Cahn, has evolved since its creation in the 1960s. In 1990, the World Wide Web transformed...


Then sign up for FREE to the ehacking’s exclusive group. You will get the exclusive tips/tricks, tutorials, webinars & courses that I ONLY share with my fellow on this exclusive newsletter.